1. Field of the Art
The present invention generally relates to an outboard motor with a cowling, and more particularly relates to an outboard motor that has a cowling enclosing an engine therein.
2. Description of Related Art
An outboard motor typically comprises a housing unit that can be mounted on an associated watercraft. An internal combustion engine is disposed above the housing unit. Typically, a propeller is journaled on a lower part of the housing unit. The engine powers the propeller through a driveshaft and a propeller shaft both extending through the housing unit. In order to protect the engine from objects and water, a cowling surrounds the engine.
The cowling defines a generally closed cavity around the engine. The cowling has an air inlet port through which the atmospheric air enters the cavity. The engine draws the air into one or more combustion chambers to burn fuel which is also delivered into the combustion chambers. Relatively cool air is preferable for the engine because the cool air can make the charging efficiency better and, as a result, can improve the output of the engine.
Typically, the cowling is made of a plastic material. Because such a plastic cowling has in sufficient heat radiation and engines normally build heat while operating, the air in the cavity can become warm, deteriorating the charging efficiency of the engine.